<正> Objective: To investigate the relationship between oxidative stress and apoptosis and bcl-2 expression fol-lowing traumatic brain injury （TBI）. Methods: Male Sprague-Dawley ras were subjected to lateral fluid percussionbrain injury （FPBI） of moderate severity. U-74389G （20 mg/kg） were administered intravenously before FPBI. Theneurological functions were measured by beam-walk task （BWT） and beam-balance task （BBT）. In addition to mor-phological evidence of apoptosis

TUNEL histochemistry was used to identify DNA fragmentation in situ with both lightand electron microscopic levels. The internucleosomal fragments of DNA in apoptotic cells were examined using agarose